A technique for appropriately supplying and receiving electric power between a plurality of power supplies and a load device (for example, a rotating electric machine or the like) has conventionally been known. For example, Japanese Patent Laying-Open No. 2008-109840 (Patent Document 1) discloses a power supply system capable of deriving the system performance to the maximum extent even when a plurality of power storage devices have respective charge/discharge characteristics different from each other. This power supply system is a power supply system capable of supplying and receiving electric power to and from a load device, and includes: a plurality of chargeable power storage devices; an electric power line for supplying and receiving electric power between the power supply system and the load device; a plurality of converters provided in association with the plurality of power storage devices, each of which performs voltage conversion between an associated power storage device and the electric power line; and a control device controlling the plurality of converters. The control device includes a share ratio calculation unit performing at least one of a first calculation to determine a discharge power share ratio between respective electric powers to be discharged from the plurality of power storage devices and a second calculation to determine a charge power share ratio between respective electric powers to be used for charging the plurality of power storage devices, and a converter control unit performing at least one of a first control to control the plurality of converters according to the discharge power share ratio when electric power is supplied from the power supply system to the load device and a second control to control the plurality of converters according to the charge power share ratio when electric power is supplied from the load device to the power supply system. The first calculation is performed to determine, for each of the plurality of power storage devices, a remaining electric power quantity before a state of charge is reached with respect to which allowable discharge electric power is restricted, and determine the discharge power share ratio according to a ratio of the remaining electric power quantity between the plurality of power storage devices. The second calculation is performed to determine, for each of the plurality of power storage devices, a chargeable quantity before a state of charge is reached with respect to which allowable charge electric power is restricted, and determine the charge power share ratio according to a ratio of the chargeable quantity between the plurality of power storage devices.
According to the power supply system disclosed in the publication described above, an opportunity allowing realization of maximal charge and discharge characteristics as the power supply system as a whole is maximized. Consequently, even though the charge and discharge characteristics are different among the plurality of storage devices, maximum performance of the power supply system can be exhibited.    Patent Document 1: Japanese Patent Laying-Open No. 2008-109840